Abstract: In a variable valve opening property internal combustion engine, a roller link (22) is provided with a cam roller (31) at a free end thereof which engages a cam (3) of a camshaft (4) and a pressure surface (47) of a spring device (41). The roller link is pivotally supported by a bearing portion of a control link (21) which can be adjusted in position by using an actuator (14). The roller link is additionally provided with a roller shaft (31) that engages a slipper surface of a rocker arm (6). The pressure surface of the spring device may be contoured or otherwise inclined so that the direction of action of the spring device on the cam roller can be directed in an optimum direction irrespective of the adjusted position of the pivot point of the roller link.

Abstract: An engine valve operating system is provided in which a roller in rolling contact with a valve operating cam of a camshaft is axially supported via a roller shaft on a roller support portion provided on a first rocker arm, a second rocker arm having a cylindrical boss portion pivotably supported on a support shaft and an arm portion extending from the boss portion and having a sliding surface that is in sliding contact with the roller shaft is operatively connected to an engine valve, and the position of either one of first and second rocker arm swing axes is changed within a plane perpendicular to the axis of the camshaft, wherein at least the roller support portion (38) of the first rocker arm (23) is disposed at a position that overlaps the second rocker arm (26A, 26B) in plan view. This can provide an engine valve operating system that enables the size thereof to be reduced in a direction along the axis of the camshaft.

Abstract: Provided is a variable valve lift internal combustion engine including a control shaft pivotally supported by a cylinder head via a pivot arm pivotally supported by the cylinder head so as to able to move angularly around a rotational center line extending in parallel with an axial line of the control shaft, a power transmitting member supported by the control shaft, an actuator for causing an angular movement of the control shaft around the rotational center line via the power transmitting member and a control arm having a base end pivotally supported by the control shaft and a free end interposed between a cam lobe of an engine camshaft and a part of a rocker arm. The lift of the engine valve can be varied by angularly moving the control shaft around the rotational center line and moving the base end of the control arm.

Abstract: An engine valve operating system is provided in which a roller in rolling contact with a valve operating cam of a camshaft is axially supported via a roller shaft on a roller support portion provided on a first rocker arm, a second rocker arm having a cylindrical boss portion pivotably supported on a support shaft and an arm portion extending from the boss portion and having a sliding surface that is in sliding contact with the roller shaft is operatively connected to an engine valve, and the position of either one of first and second rocker arm swing axes is changed within a plane perpendicular to the axis of the camshaft, wherein at least the roller support portion (38) of the first rocker arm (23) is disposed at a position that overlaps the second rocker arm (26A, 26B) in plan view. This can provide an engine valve operating system that enables the size thereof to be reduced in a direction along the axis of the camshaft.

Abstract: In a variable valve opening property internal combustion engine, a control shaft (20) is supported by a control link (21) which is in turn is pivotally supported by a cylinder head (1), and a roller link (22) is pivotally supported by the control shaft. The roller link is provided with a cam roller (31) that engages a cam (3) of a camshaft (4) and a roller shaft (32) that engages a slipper surface (33) of a rocker arm (6). The arcuate movement of the cam roller centered around the control shaft varies the swing of the rocker arm and hence the valve lift in dependence on the position of the control shaft. A compression coil spring (41) is interposed between a part of the cylinder head and a side of the cam roller facing away from the cam. The coil spring is oriented such that a direction of a spring force (Fspg) substantially coincides with a direction of a guided movement of the cam roller, preferably in a low valve lift condition.

Abstract: In a variable valve opening property internal combustion engine, a roller link (22) is provided with a cam roller (31) at a free end thereof which engages a cam (3) of a camshaft (4) and a pressure surface (47) of a spring device (41). The roller link is pivotally supported by a bearing portion of a control link (21) which can be adjusted in position by using an actuator (14). The roller link is additionally provided with a roller shaft (31) that engages a slipper surface of a rocker arm (6). The pressure surface of the spring device may be contoured or otherwise inclined so that the direction of action of the spring device on the cam roller can be directed in an optimum direction irrespective of the adjusted position of the pivot point of the roller link.

Abstract: Provided is a variable valve lift internal combustion engine including a control shaft pivotally supported by a cylinder head via a pivot arm pivotally supported by the cylinder head so as to able to move angularly around a rotational center line extending in parallel with an axial line of the control shaft, a power transmitting member supported by the control shaft, an actuator for causing an angular movement of the control shaft around the rotational center line via the power transmitting member and a control arm having a base end pivotally supported by the control shaft and a free end interposed between a cam lobe of an engine camshaft and a part of a rocker arm. The lift of the engine valve can be varied by angularly moving the control shaft around the rotational center line and moving the base end of the control arm.